Container Service for Kubernetes:Collect the metrics of the specified virtual node

Managed Service for Prometheus

By default, this feature is provided in clusters. No additional configuration is required.

Open-source Prometheus Operator

If you use open-source Prometheus Operator or ack-prometheus-operator from the add-ons of ACK, you must add the following ServiceMonitor CustomResource (CR):

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  name: virtual-kubelet
  namespace: monitoring
  labels:
    k8s-app: kubelet
    # Add this label to automatically manage prometheus-operator. 
    release: prometheus-operator
spec:
  jobLabel: k8s-app
  selector:
    matchLabels:
      k8s-app: kubelet
  namespaceSelector:
    matchNames:
    - kube-system
  endpoints:
  - port: https-metrics
    interval: 15s
    scheme: https
    path: /metrics/cadvisor
    bearerTokenFile: /var/run/secrets/kubernetes.io/serviceaccount/token
    tlsConfig:
      caFile: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      insecureSkipVerify: true
    relabelings:
    # Retain only the virtual node endpoint. 
    - sourceLabels: [__meta_kubernetes_endpoint_address_target_name]
      regex: (^virtual-kubelet.*)
      action: keep
    # Add parameters to query based on the specified nodeName. 
    - sourceLabels: [__meta_kubernetes_endpoint_address_target_name]
      regex: (^virtual-kubelet.*)
      targetLabel: __param_nodeName
      replacement: ${1}
      action: replace

If the cluster is already configured with service discovery to collect cAdvisor metrics based on the kubelet Service, you must add the following configuration to discard the <Virtual Node IP>:10250/metrics/cadvisor endpoint in case duplicate data is collected.

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
...
spec:
  endpoints:
  - path: /metrics/cadvisor
    port: https-metrics
    ...
    relabelings:
    # The relabeling rule discards the endpoints of all targets whose names start with virtual-kubelet.
    - action: drop
      regex: (^virtual-kubelet.*)
      sourceLabels:
      - __meta_kubernetes_endpoint_address_target_name

Open-source Prometheus

Find the configuration file of open-source Prometheus. Normally, you can find the configuration file in /etc/prometheus/prometheus.yml or in your custom configuration directory. Then, add the following collection configuration to the file:

scrape_configs:

...Other job configuration. 

- job_name: monitoring/virtual-kubelet/0
  honor_timestamps: true
  scrape_interval: 15s
  scrape_timeout: 10s
  metrics_path: /metrics/cadvisor
  scheme: https
  bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
  tls_config:
    ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
    insecure_skip_verify: true
  relabel_configs:
  - source_labels: [__meta_kubernetes_service_label_k8s_app]
    separator: ;
    regex: kubelet
    replacement: $1
    action: keep
  - source_labels: [__meta_kubernetes_endpoint_port_name]
    separator: ;
    regex: https-metrics
    replacement: $1
    action: keep
  - source_labels: [__meta_kubernetes_endpoint_address_target_kind, __meta_kubernetes_endpoint_address_target_name]
    separator: ;
    regex: Node;(.*)
    target_label: node
    replacement: ${1}
    action: replace
  - source_labels: [__meta_kubernetes_endpoint_address_target_kind, __meta_kubernetes_endpoint_address_target_name]
    separator: ;
    regex: Pod;(.*)
    target_label: pod
    replacement: ${1}
    action: replace
  - source_labels: [__meta_kubernetes_namespace]
    separator: ;
    regex: (.*)
    target_label: namespace
    replacement: $1
    action: replace
  - source_labels: [__meta_kubernetes_service_name]
    separator: ;
    regex: (.*)
    target_label: service
    replacement: $1
    action: replace
  - source_labels: [__meta_kubernetes_pod_name]
    separator: ;
    regex: (.*)
    target_label: pod
    replacement: $1
    action: replace
  - source_labels: [__meta_kubernetes_pod_container_name]
    separator: ;
    regex: (.*)
    target_label: container
    replacement: $1
    action: replace
  - source_labels: [__meta_kubernetes_service_name]
    separator: ;
    regex: (.*)
    target_label: job
    replacement: ${1}
    action: replace
  - source_labels: [__meta_kubernetes_service_label_k8s_app]
    separator: ;
    regex: (.+)
    target_label: job
    replacement: ${1}
    action: replace
  - separator: ;
    regex: (.*)
    target_label: endpoint
    replacement: https-metrics
    action: replace
  - source_labels: [__meta_kubernetes_endpoint_address_target_name]
    separator: ;
    regex: (^virtual-kubelet.*)
    replacement: $1
    action: keep
  - source_labels: [__meta_kubernetes_endpoint_address_target_name]
    separator: ;
    regex: (^virtual-kubelet.*)
    target_label: __param_nodeName
    replacement: ${1}
    action: replace
  kubernetes_sd_configs:
  - role: endpoints
    namespaces:
      names:
      - kube-system

If the cluster is already configured with service discovery to collect cAdvisor metrics based on the kubelet Service, you need to add the following configuration to discard the <Virtual Node IP>:10250/metrics/cadvisor endpoint in case duplicate data is collected.

scrape_configs:

...Other job configuration. 

- job_name: monitoring/ack-prometheus-operator-kubelet/0
  honor_labels: true
  honor_timestamps: true
  ...
  relabel_configs:
  ...
  // Discard the endpoint for collecting the /metrics/cadviso metrics of virtual nodes. 
  - source_labels: [__meta_kubernetes_endpoint_address_target_name]
    separator: ;
    regex: (^virtual-kubelet.*)
    replacement: $1
    action: drop